@article {47084,
	title = {Green-to-red photoconversion of GCaMP.},
	journal = {PLoS One},
	volume = {10},
	year = {2015},
	month = {2015 Sep 18},
	pages = {e0138127},
	abstract = {<p>Genetically encoded calcium indicators (GECIs) permit imaging intracellular calcium transients. Among GECIs, the GFP-based GCaMPs are the most widely used because of their high sensitivity and rapid response to changes in intracellular calcium concentrations. Here we report that the fluorescence of GCaMPs-including GCaMP3, GCaMP5 and GCaMP6-can be converted from green to red following exposure to blue-green light (450-500 nm). This photoconversion occurs in both insect and mammalian cells and is enhanced in a low oxygen environment. The red fluorescent GCaMPs retained calcium responsiveness, albeit with reduced sensitivity. We identified several amino acid residues in GCaMP important for photoconversion and generated a GCaMP variant with increased photoconversion efficiency in cell culture. This light-induced spectral shift allows the ready labeling of specific, targeted sets of GCaMP-expressing cells for functional imaging in the red channel. Together, these findings indicate the potential for greater utility of existing GCaMP reagents, including transgenic animals.</p>
},
	issn = {1932-6203},
	doi = {10.1371/journal.pone.0138127},
	author = {Ai, Minrong and Mills, Holly and Kanai, Makoto and Lai, Jason and Deng, Jingjing and Schreiter, Eric and Looger, Loren and Neubert, Thomas and Suh, Greg}
}
